Stop-switching apparatus for engine-driven compressors



Au 13, 1929. F, A KERM N 1,723,996

STOP SWITCHING APPARATUS FOR ENGINE DRIVEN COMPRESSORS Filed June 12, 1925 jA/VENTOR War 0, B y w /47 TO ENE vs Patented Aug. 13, 1929.

FRANK AOKERMAN, OF ST. LOUIS, MISSOURI, ASSIGNOR T0 CURTIS MANUFACTURING COMPANY, OF WELLSTON, MISSOURI, A CORPORATION OF MISSOURI.

STOP-SWITCHING APPARATUS FOR ENGINE-DRIVEN COMPRESSORS.

Application filed June 12,

This invention relates to a stopping apparatus of novel construction that is adapted to be used for automatically stopping an engine used for driving a compressor when the pressure of the medium in the storage tank that is connected with the compressor reaches a predetermined degree.

One object of my invention is to provide a .stopping apparatus of the kind referred tothat is inexpensive to construct and reliable in operation.

Another object is to provide an automatic stopping apparatus for an engine driven compressor which is equipped with a signal that operates automatically when the pressure in the storage tank drops below a predetermined degree, thus notifying the operator in charge of the compressor that the engine should be started so as to raise the pressure in the storage tank.

Figure 1 is a side elevational View of an engine driven air compressor equipped with a stopping apparatus constructed in accordance with my invention.

Figure 2 is an enlarged side elevational view of said apparatus; and

Figure 3 is a vertical sectional view, taken on the line 3-3 of Figure 2, looking in the direction indicated by the arrows.

In the drawings A designates an internal combustion engine, B designates a compressor that is driven by said engine and O designates a storage tank for receiving the medium compressed by the compressor. My improved apparatus is used for automatically stopping the engine A when a predetermined maximum pressure is reached in the storage tank C and for operating a signal D whenever the pressure in the storage tank drops below a predetermined minimum pressure. The apparatus can be constructed in various ways and it can be used in connection with various types and kinds of engines. I have herein illustrated the apparatus as beingdesigned for use with an internal combustion engine equipped with an electrical ignition mechanism, and when constructed in this manner, the stopping of the engine is etlected by grounding the ignition circuit.

The apparatus comprises a pressure operated' member 1, preferably a flexible diaphragm, arranged so that when a certain maximum pressure is reached in the storage tank C, said member 1 will cause a change to take place in the condition of the ignition 1926. Serial No. 115,608.

mechanism of the engine A that results in the stopping of said engine. lVhen the pressure in the storage tank C drops to a certain minimum pressure, the signal D operates automatically, thus notifying the operator that the engine should be started so as to raise the pressure in the storage tank. In the preferred form of my invention, as herein illustrated, a grounding device consisting of a pivotally mounted lever 2 is normally held in an inactive position by means of a latch 3, and when the predetermined maximum pressure is reached, the pressure-operated member 1 discngages said latch 3 from the grounding device 2, thereby permitting a spring 4 to move said grounding device into engagement with a contact 5 and cause the ignition mechanism of the engine A to be grounded. The diaphragm 1 is arranged so that the pressure in the storage tank C is normally exerted on said diaphragm in a direction tending to flex it upwardly, and a spring-pressed plunger 6 is arranged above the diaphragm so as to resist the upward movement of the diaphragm, the actuating spring 7 of the plunger 6 being combined with a nut 8 that is adapted to be adjusted so as to vary the tension of said spring. The diaphragm 1 is clamped between a base plate 9 and a member 10 that houses the plunger 6, and the latch 3, previously referred to, is pivotally mounted on a pin 11 carried by a bracket 12 on the housing 10. The grounding lever 2 is pivotally mounted on a supporting standard 13, and the contact 5 with which the grounding lever 2 co-operates is carried by a piece 14 of fibre or other suitable insulating material, as shown in Figure 2.

Any suitable type of signal D may be used, either an audible or visual signal, but I prefer to use an audible signal consisting of a bell arranged in an electric circuit provided with a switch that is held in its open position, so long as the pressure in the storage tank C exceeds the predetermined minimum pressure, and which moves automatically into its closed position whenever the pressure in the tank 0 reaches or drops below the predetermined minimum pressure. The switch that governs the signal circuit comprises a movable switch member herein illustrated as a lever 15 pivotally mounted on the pin 11 and provided with a portion that is interposed between the underside of the latch 3 and the upper end of the plunger 6, said switch member being arranged above an adjustable, contact 16 in the signal circuit carried by a binding post 17 on the in sulator 14. The Contact 16'is adapted to be set in such a position that the diaphragm 1 operating in conjunction with the plunger 6 will hold the switch member 15 out of engagement with said contact 16 when the pressure in the tank 0 is above the predetermined minimum pressure, and when the pressure in said tank drops below said minimum, the switch member 15 will be moved downwardly into engagement with the contact 16 by a spring, weight or other suitable means, herein illustrated as a weighted lever 18, pivotally mounted on the pin 11 and arranged so that it normally exerts pressure on the switch member 15 in a direction tending to move said member towards the contact 16. In the form of my invention herein illustrated the switch member 15 is channel-shaped 1n cross section .and is arranged so that it embraces the latch I connection 19 arranged in alignment with a hole in the base plate 9 which permits the pressure in the tank G to be exerted on the diaphragm 1. A wire 00 that leads from the spark plug or magneto of the ignition mechanism of the engine A is then connected to the contact 5 on the insulator 14 and aground wire 3/ whichleads from the frame or some other metallic part of the engine A is then connected to the bracket 12 on the housing 10 by means of a binding screw 20. The signal circuit is then connected with the switch that controls the signal D by attaching the wire 2? of the signal circuit to the binding screw 20 on the bracket 12 and attaching the wire 10 of the signal circuit to the binding post 17 so as to establish electrical connection between said wire 10 and the contact 16. In adjusting the apparatus the weighted lever 18 is arranged in the position shown in full lines in Figure 2 and the latch 3 is arranged in engagement with the upper end of the grounding lever 2 so as to hold said grounding lever out of engagement with, the

contact 5. After the engine A has been startedso as to raise the pressure in the storage tank-C, the nut 8 that governs the tension of the spring 7 is backed off slowly so as to permit the plunger 6to move upwardly and exert upward pressure on the switch member 15 that embraces the latch 3, said nut Sbeing backed oflf until the predetermined maximum pressure is reached, whereupon the latch 3 will move upwardly out of engagement with the grounding member 2, due to the upward pressure exerted on said latch by the switch member 15, the plunger 6 and the diaphragm 1. As soon as the latch 3 is disengaged from the grounding lever 2, said lever will move under the influence of the spring 4: into engagement with the contact 5, thereby grounding the ignition mechanism of the engine A and causing said engine to stop. The pressure in the storage tank C is then reduced and at the same time the contact 16 is backed off or screwed downwardly. When the pressure in the storage tank is reached that is to constitute the minimum pressure, the contact 16 is locked in adjusted position, so that it will cooperate with the switch member 15 to close the signal circuit whenever the pressure in the storage tank thereafter drops to or below the minimum pressure.

After being adjusted in the manner above described the engine A can be set in operation .so as to raise the pressure in the storage tank lever 18 to the left into the position shown in broken lines in Figure 2, so as to cause said lever to swing the switch member 15 upwardly, and thus cause the latch 3 to be disengaged from the grounding lever 2, which immediately moves into engagement with the contact 5, thus grounding the ignition mechanism of the engine. At night or at other times when it is not necessary to maintain a certain approximate pressure in the storage tank C, the lever 18 is arranged in the position shown in broken lines in Figure 2, so as to prevent thesignal circuit being closed should the pressure in the storage tank drop below the minimum,-the bracket 12 on the housing 10 being provided with a supporting lug 21011 which the lever 18 rests at such times.

A stopping apparatus of the construction above described is inexpensive to construct, it is easy to install and adjust and it is of such simple design that it is absolutely reliable for the use for which it is intended. 7

Having thus described my invention, what- I claim as new and desire to secure by Letters Patent is:

1. An apparatus for the purpose described, comprising a base plate, a spring-actuated, pivotally mountedgrounding lever carried by. said base plate, a latch for holding said groimdinglever in an inactive position, a diaphragm'on said base plate adapted to be-fiexed in one direction by the pressure in a storage tank,a spring-actuated plunger for resisting movement of said diaphragm in one direction,

said plunger being adapted to be actuated by said diaphragm to trip said latch, means for varying the tension of the spring of said plunger, a switch comprising a switch member arranged between said latch and a contact in the switch circuit, and a means capable of exerting pressure on said switchmember in adirection tending to move it towards its cooperating contact when said latch is disengaged from said grounding lever.

2. An apparatus for the purpose described, comprising a base plate adapted to be connected to a storage tank, a diaphragm on said base plate arranged so that it will be flexed in one direction by the pressure in said tank, a spring-actuated plunger for flexing the diaphragm in an opposite direction, a spring-actuated grounding lever carried by said base plate, a latch for holding said grounding lever in an inactive condition, adapted to be tripped by said plunger, an insulator provided with a contact, a pivotally mounted switch member arranged between said latch and the upper end of said plunger, and a pivotally mounted, weighted lever that normally exerts pressure on said switch member in a direction tending to hold it in engagement with said plunger whereby movement of said plunger under the influence of its spring after said latch has been tripped causes said switch member to engage said contact.

3. An apparatus for the purpose described, comprising an automatically operating stopping member, a pivotally mounted latch for holding said stopping member in an inactive position, a diaphragm adapted to be flexed in one direction by the pressure in a storage tank, a spring-actuated plunger for tripping said latch arranged so as to resist movement of said diaphragm in one direction, and a switch comprising a switch member interposed between said latch and said plunger whereby movement of said diaphragm resulting from a diminution of the pressure in the storage tank causes said switch member to become operative when the pressure in the storage tank reaches a predetermined minimum.

4. An apparatus for the purpose described, comprising an automatically operating stop pin member, a pivotally mounted latch for hol ing said stopping member in an inactive position, a diaphragm adapted to be flexed in one direction by the pressure in a storage tank causes said switch member to become operative when the pressure in the storage tank reaches a predetermined minimum, and a means that is adapted to be actuated to hold said switch member in engagement with said plunger or out of engagement with said plunger.

5. An apparatus for the purpose described, comprising a base plate adapted to be connected to a storage tank, a diaphragm on said base plate that is adapted to be flexed in one direction by the pressure in said tank, a spring-actuated plunger arranged above said diaphragm for flexing the diaphragm in the opposite direction, an automatically-operating stopping member, a pivotally mounted latch for holding said stopping member in an inactive position arranged above said plunger and adapted to be actuated by same to release the stopping member, and a pivotally mounted switch member interposed between the underside of said latch and the upper end of said plunger, for the purpose described.

6. An apparatus for the purpose described, comprising a base plate adapted to be connected to a storage tank, a diaphragm on said base plate that is adapted to be flexed in one direction by the pressure in said tank, a spring-actuated plunger arranged above said diaphragm for flexing the diaphragm in the opposite direction, an automatically-operating stopping member, a pivotally mounted latch for holding said stopping member in an inactive position arranged above said plunger and adapted to be actuated by same to release the stopping member, a pivotally mounted switch member interposed between the underside of said latch and the upper end of said plunger, for the purpose described, and a pivotally mounted, weighted lever adapted to be arranged in one position wherein it holds said switch member in engagement with the upper end of said plunger and in a different position wherein it holds said switch member in an inactive position.

FRANK ACKERMAN. 

